Yeah the MC has lost it. He doesn't have a clear vision of revenge now he is gonna send people to hell just because they were in the general vicinity when he was executed. He is looking for excuses to torture people now and he has the power and his own twisted sense of justice to do it. No...
The author couldn't decide on anything so he did all of it, then immediately retcons them all to show us they were not endings but "possible futures". This is the laziest, lamest, most unnecessary way of ending a Manga.
If you came here for the eechi, you have come to the wrong place. Good start, somewhat ok middle, below average ending, forgettable characters without any noticeable traits. I don't recommend it. Maybe 4/10.